<template>
  <div class="upload-file">
    <el-upload
      ref="fileUpload"
      :action="uploadUrl!==undefined?(baseUrl+uploadUrl): uploadFileUrl"
      :before-upload="handleBeforeUpload"
      :file-list="fileList"
      :headers="headers"
      :limit="limit"
      :on-error="handleUploadError"
      :on-exceed="handleExceed"
      :on-success="handleSuccess"
      :show-file-list="false"
      class="upload-file-uploader"
    >
      <!-- 上传按钮 -->
      <el-button size="mini" type="primary">选取文件</el-button>
      <!-- 上传提示 -->
      <div v-if="showTip" slot="tip" class="el-upload__tip">
        请上传
        <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
        <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join('/') }}</b></template>
        的文件
      </div>
    </el-upload>

    <!-- 文件列表 -->
    <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul">
      <li v-for="(file, index) in fileList" :key="file.url" class="el-upload-list__item ele-upload-list__item-content">
        <el-link :href="`${baseUrl}${file.url}`" :underline="false" target="_blank">
          <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
        </el-link>
        <div class="ele-upload-list__item-content-action">
          <el-link :underline="false" type="danger" @click="handleDelete(index)">删除</el-link>
        </div>
      </li>
    </transition-group>


    <el-dialog title="错误信息" :visible.sync="showErrorData">
      <el-table :data="errorData">
        <el-table-column prop="rowIndex" label="行号" width="60px"/>
        <el-table-column prop="columnIndex" label="索引" width="60px"/>
        <el-table-column prop="columnStr" label="列号" width="60px"/>
        <el-table-column prop="columnName" label="列名" width="150px"/>
        <el-table-column prop="errMsg" label="错误消息"/>
      </el-table>

      <div slot="footer" class="dialog-footer">
        <el-button @click="showErrorData=false">取消</el-button>
      </div>
    </el-dialog>
  </div>
</template>

<script>
import { getToken } from '@/utils/auth'
import { log } from '@/api/common'

export default {
  name: 'FileUpload',
  props: {
    fileUploadSuccess: {},
    // 值
    value: [String, Object, Array],
    // 数量限制
    limit: {
      type: Number,
      default: 5
    },
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 5
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array,
      default: () => ['docx', 'xlsx', 'pptx', 'txt', 'pdf']
    },
    // 是否显示提示
    isShowTip: {
      type: Boolean,
      default: true
    },
    uploadUrl: {
      type: String
    }
  },
  data() {
    return {
      number: 0,
      showErrorData: false,
      uploadList: [],
      baseUrl: process.env.VUE_APP_BASE_API,
      uploadFileUrl: process.env.VUE_APP_BASE_API + '/fileUpload/insert', // 上传文件服务器地址
      headers: { 'j-token': getToken() },
      fileList: [],
      errorData: [
        {
          columnIndex: null,
          columnName: '未知',
          columnStr: '',
          errMsg: '库存不能为空',
          rowIndex: 1
        }]
    }
  },
  watch: {
    value: {
      handler(val) {
        if (val) {
          let temp = 1
          // 首先将值转为数组
          const list = Array.isArray(val) ? val : this.value.split(',')
          // 然后将数组转为对象数组
          this.fileList = list.map(item => {
            if (typeof item === 'string') {
              item = { name: item, url: item }
            }
            item.uid = item.uid || new Date().getTime() + temp++
            return item
          })
        } else {
          this.fileList = []
          return []
        }
      },
      deep: true,
      immediate: true
    }
  },
  computed: {
    // 是否显示提示
    showTip() {
      return this.isShowTip && (this.fileType || this.fileSize)
    }
  },
  methods: {
    // 上传前校检格式和大小
    handleBeforeUpload(file) {
      // 校检文件类型
      if (this.fileType) {
        const fileName = file.name.split('.')
        const fileExt = fileName[fileName.length - 1]
        const isTypeOk = this.fileType.indexOf(fileExt) >= 0
        if (!isTypeOk) {
          this.$modal.msgError(`文件格式不正确, 请上传${this.fileType.join('/')}格式文件!`)
          return false
        }
      }
      // 校检文件大小
      if (this.fileSize) {
        const isLt = file.size / 1024 / 1024 < this.fileSize
        if (!isLt) {
          this.$modal.msgError(`上传文件大小不能超过 ${this.fileSize} MB!`)
          return false
        }
      }
      this.$modal.loading('正在上传文件，请稍候...')
      this.number++
      return true
    },
    // 文件个数超出
    handleExceed() {
      this.$modal.msgError(`上传文件数量不能超过 ${this.limit} 个!`)
    },
    // 上传失败
    handleUploadError(err) {
      this.$modal.msgError('上传文件失败，请重试')
      this.$modal.closeLoading()
    },
    // 上传成功回调
    handleUploadSuccess(res, file) {
      if (res.code === 200) {
        this.uploadList.push({ name: res.fileName, url: res.fileName })
        this.uploadedSuccessfully()
      } else {
        this.number--
        this.$modal.closeLoading()
        this.$modal.msgError(res.msg)
        this.$refs.fileUpload.handleRemove(file)
        this.uploadedSuccessfully()
      }
    },
    // 删除文件
    handleDelete(index) {
      this.fileList.splice(index, 1)
      this.$emit('input', this.listToString(this.fileList))
    },
    // 上传结束处理
    uploadedSuccessfully() {
      if (this.number > 0 && this.uploadList.length === this.number) {
        this.fileList = this.fileList.concat(this.uploadList)
        this.uploadList = []
        this.number = 0
        this.$emit('input', this.listToString(this.fileList))
        this.$modal.closeLoading()
      }
    },
    // 获取文件名称
    getFileName(name) {
      if (name.lastIndexOf('/') > -1) {
        return name.slice(name.lastIndexOf('/') + 1)
      } else {
        return ''
      }
    },
    // 对象转成指定字符串分隔
    listToString(list, separator) {
      let strs = ''
      separator = separator || ','
      for (let i in list) {
        strs += list[i].url + separator
      }
      return strs !== '' ? strs.substr(0, strs.length - 1) : ''
    },
    handleSuccess(res) {
      log('file upload handleSuccess', res)
      if (res.errorData) {
        this.errorData = res.errorData
        this.showErrorData = true
        this.$modal.closeLoading()

      } else {

        this.fileUploadSuccess(res)
        // this.value = [res.data.id];
        this.fileList = []
        this.$modal.closeLoading()

      }

    }
  }
}
</script>

<style lang="scss" scoped>
.upload-file-uploader {
  margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}

.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}

.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>
